Barcelona will ensure the title this season when they face Espanyol. If they win the match then Barcelona has locked the title in the match. Indeed, Espanyol performance in their season was quite bad, they even found it difficult to provide good resistance against their opponents. Therefore I'm pretty sure Barcelona will win the game maybe even by a big score.
I'm also sure that Barcelona will win even if not by a large score, because Barcelona just wants to confirm the championship earlier with the victory they will achieve in the match with Espanyol. Apart from that, Espanyol is indeed not a challenge that is so difficult for Barcelona so that Barcelona will only try to play as best as possible for full points even if they only win with not many scores.
Espanyol are in 19th place in the standings, they are fighting to get out of the relegation zone but this week's opponent is Barcelona and it is difficult for them to beat barcelona.
I believe that Espanyol will not be able to get out of the relegation zone this season because of the next five matches that Espanyol will face, there are three matches that might be very tough for Espanyol (including the game with Barcelona). In addition, Espanyol is also three points behind Getafe and Valencia, who are ranked 17th and 18th in the standings, so that makes it a little difficult for Espanyol to level points with the two teams.